Human beings, equipped with more genes than lesser creatures, are consequently smarter than other beasts. Right? Wrong. A frantic competition between two philosophies for deciphering the entire human genome has, in one of its important accomplishments, deflated this long-standing presumption. Both competitors agree on an estimate that humans have about 30,000 genes, which is roughly the same as a mouse's inventory of genes and well below earlier estimates of as much as 100,000 human genes. Furthermore, humans possess only 300 genes not found in mice.